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On contact of liquid with a surface, adhesion forces result in wetting of the surface. Either complete or incomplete wetting may occur depending on the structure of the surface and the fluid tension of the droplet. [12] The cause of self-cleaning properties is the hydrophobic water-repellent double structure of the surface. [13]
Differential adhesion hypothesis (DAH) is a hypothesis that explains cellular movement during morphogenesis with thermodynamic principles. In DAH tissues are treated as liquids consisting of mobile cells whose varying degrees of surface adhesion cause them to reorganize spontaneously to minimize their interfacial free energy. [1]
Note 1: Adhesion requires energy that can come from chemical and/or physical linkages, the latter being reversible when enough energy is applied. Note 2: In biology, adhesion reflects the behavior of cells shortly after contact to the surface. Note 3: In surgery, adhesion is used when two tissues fuse unexpectedly. [1]
One example of a superhydrophobic surface in nature is the Lotus leaf. [12] Lotus leaves have a typical contact angle of θ ∼ 160 ∘ {\displaystyle \theta \sim 160^{\circ }} , ultra low water adhesion due to minimal contact areas, and a self cleaning property which is characterised by the Cassie-Baxter equation. [ 13 ]
To incorporate the effect of adhesion in Hertzian contact, Johnson, Kendall, and Roberts [5] formulated the JKR theory of adhesive contact using a balance between the stored elastic energy and the loss in surface energy. The JKR model considers the effect of contact pressure and adhesion only inside the area of contact.
This occurs between water and glass. Water-based fluids like sap, honey, and milk also have a concave meniscus in glass or other wettable containers. Conversely, a convex meniscus occurs when the adhesion energy is less than half the cohesion energy. Convex menisci occur, for example, between mercury and glass in barometers [1] and thermometers.
Paint can peel for a variety of reasons, including too much moisture, using the wrong product, and poor wall preparation. Poor Wall Preparation A successful paint job depends on how carefully you ...
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged.